why is breastfeeding best

boobs. they’re complicated, and they’re alsocannibals. well, sort of… hey mammary-gland mavens, julian here fordnews. so we all know that after women give birth,their breasts swell to become milk machines for their newborns. but biologists have long tried to explainhow, when a woman stops producing milk for breastfeeding, the breasts shrink back tonormal size in a matter of days. new research gives us some answers – theyeffectively “eat” themselves to regenerate.

according to a september 2016 study in thejournal developmental cell, when a woman is done lactating, certain cells in her breastconsume other dead neighboring cells, which are left over from the breastfeeding process. in other words, the breast’s cells turnon each other and become cannibals! whoa! before we go into the details, we have toknow more about how breasts work. breasts are made up of a network of ducts,surrounded by a layer of fatty tissue. when a woman is pregnant, hormones increasethe number of epithelial cells that line these ducts.

epithelial cells line our skin, digestivetract and other internal organs, acting as a barrier between our bodies and contaminantsin the environment; and depending on where they are in the body, they can perform differentfunctions -- like allowing us to taste, touch and smell, or secreting mucus to process nutrients. when these cells increase in the breast ducts,they form alveoli, tiny sacs that hold the milk. but when a woman stops breastfeeding, thesacs self-destruct and become debris that needs to be removed. and they do so with the help of a pac-man-likeprotein called rac1.

normally, the body’s immune cells get ridof foreign matter in a different way – a process called phagocytosis. this complex series of steps allows immunecells called phagocytes to identify dead and dying cells and destroy them, which causesinflammation, pain and tissue damage. but women who finish breastfeeding don’ttypically experience the pain associated with this process– so scientists surmised thatsomething else must be responsible for the clean-up of dead cells. they singled out the protein rac1, which playsa key role in both milk production and phagocytosis. to investigate, they bred a litter of micethat couldn’t produce the protein.

then those mice reproduced. turns out, most of their pups didn’t survivebecause their mice mothers stopped being able to produce milk for them. the lack of rac1 caused a buildup of deadcells, which blocked normal milk production. excess milk then accumulated in the breasttissue, which became inflamed and swollen. this showed that rac1 is crucial for gettingrid of dead cells and preventing harmful inflammatory responses. it also seemingly keeps dead cells attachedto the alveoli for longer, encouraging the epithelial cells to eat each other.

it’s possible that this cell-eating-cellprocess happens in other organs, since epithelial cells form the building blocks of our bodies. scientists in the same study noted that itis thought humans shed the equivalent of their own body weight in dead cells every year. if phagocytosis were solely responsible, we’dbe constantly inflamed... so maybe this cannibalization is happening all over your body. the findings could also provide more insightinto the development and progression of breast cancer, since lingering dead cells and resultinginflammation could allow cancer cells to grow. after all, women have an increased risk ofbreast cancer in the first five to ten years

following pregnancy and a whopping 80-90 percentof all cancers come from epithelial cells. while further research is needed, rac1 mayhave a crucial role in the development of anticancer therapies. so there you have it – a woman’s bodyheals itself by eating itself in a bizarre form of regeneration. consider yourself now a little less confusedabout women. and if you want to know more about breastmilk and maybe if it could be used as a sports drink substitute, i have a video on that rightover here. so, do you have any other questions aboutsome weird stuff the body does you want us

to look into? go ahead and let us know in the comments,subscribe for more and i will see you all next time on dnews.